The overlapping decomposition decentralized control is a kind of static feedback control system. Using overlapping information sets among subsystems, the reliability of the control system is improved. On the other hand the overlapping decomposition decentralized control systom isn't suitable for all systems waiting control. As for some systems, using overlapping decomposition decentralized control doesn't reach the desired control effect. This paper has discussed the applicability of the overlapping decomposition decentralized control offers the necessary conditions for applying this control technique, and provides theoretical basis for the wide applications of the overlapping decomposition decentralized control systems.